package com.awangyh.net.nio;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.time.LocalDateTime;
import java.util.Iterator;
import java.util.Set;

/**
 * @author: wangyanhui
 * @since: 2017/4/28
 */
public class TimeClientHandler implements Runnable {

	private String host;

	private int port;

	private Selector selector;

	private SocketChannel socketChannel;

	private volatile boolean stop;

	public TimeClientHandler(String host, int port) {
		this.host = host;
		this.port = port;

		try {
			selector = Selector.open();
			socketChannel = SocketChannel.open();
			socketChannel.configureBlocking(false);
		} catch (IOException e) {
			e.printStackTrace();
			System.exit(1);
		}
	}

	@Override
	public void run() {
        try {
            doConnect();
        } catch (IOException e) {
            e.printStackTrace();
            System.exit(1);
        }

        while (!stop) {
            try {
                selector.select(1000);
                Set<SelectionKey> selectionKeys = selector.selectedKeys();
                Iterator<SelectionKey> it = selectionKeys.iterator();
                SelectionKey key = null;
                while ( it.hasNext()) {
                    key = it.next();
                    it.remove();
                    try {
                        handleInput(key);
                    } catch( Exception e) {
                        key.cancel();
                        if ( key.channel() != null) {
                            key.channel().close();
                        }
                    }
                }

            } catch (IOException e) {
                e.printStackTrace();
                System.exit(1);
            }
        }

        if ( selector != null) {
            try {
                selector.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

    }

    private void handleInput(SelectionKey key ) throws IOException {

        if ( key.isValid()) {
            SocketChannel sc = (SocketChannel) key.channel();
            if ( key.isConnectable()) {
                if ( sc.finishConnect()) {
                    sc.register(selector, SelectionKey.OP_READ);
                    doWrite(sc);
                } else {
                    System.exit(1);
                }
            }

            if ( key.isReadable()) {
                ByteBuffer readBuffer = ByteBuffer.allocate(1024);
                int readBytes = sc.read(readBuffer);
                if ( readBytes > 0 ) {
                    readBuffer.flip();
                    byte[] bytes = new byte[readBuffer.remaining()];
                    readBuffer.get(bytes);
                    String body = new String(bytes, "UTF-8");
                    System.out.println("Now is : " + body);

                    this.stop = true;
                } else if ( readBytes < 0) {
                    key.cancel();
                    sc.close();
                } else {
                    //ignore
                }
            }

        }

    }


	private void doConnect() throws IOException {
		if (socketChannel.connect(new InetSocketAddress(host, port))) {
			socketChannel.register(selector, SelectionKey.OP_READ);
			doWrite(socketChannel);
		} else {
		    socketChannel.register(selector, SelectionKey.OP_CONNECT);
        }
	}

	private void doWrite(SocketChannel sc) throws IOException {
		byte[] req = "QUERY TIME ORDER".getBytes();
		ByteBuffer writeBuffer = ByteBuffer.allocate(req.length);
		writeBuffer.put(req);
		writeBuffer.flip();
		sc.write(writeBuffer);
		if ( !writeBuffer.hasRemaining()) {
		    System.out.println("Send order 2 server succeed.");
        }
	}
}
